The proton-proton chain is more important in stars the mass of the Sun or less.

For stars the size of the sun or smaller, the proton-proton chain dominates.

This occurs in the core region of the star using the proton-proton chain reaction process.

The first one, the proton-proton chain, is the dominant energy source in stars with masses up to about the mass of the Sun.

Though the main reactions don't involve neutrinos, the side reactions such as the proton-proton chain reaction do.

The detectors that use gallium are most sensitive to the solar neutrinos produced by the proton-proton chain reaction process.

Older stars start to accumulate helium produced by the proton-proton chain reaction and the carbon-nitrogen-oxygen cycle in their cores.

At the core, elemental hydrogen is converted to helium by a process of nuclear fusion known as the Proton-Proton chain reaction.

In the Sun, with a 10-million-kelvin core, hydrogen fuses to form helium in the proton-proton chain reaction:

The first step of the proton-proton chain reaction is a two-stage process; first, two protons fuse to form a diproton:

The first reaction in which 4 H nuclei may eventually result in one He nucleus is known as the proton-proton chain, is:

Later, with improved interior opacity calculations, it was recognized that the proton-proton chain is responsible for most of the luminosity of the Sun (Oke 1950).

In most stars the fuel is provided by hydrogen, which can combine to form helium through the proton-proton chain reaction or by the CNO cycle.

Gamow and Carl Friedrich von Weizsäcker had proposed in a 1937 paper that the Sun's energy was the result of a proton-proton chain reaction:

In stars, it is formed by the nuclear fusion of hydrogen in proton-proton chain reactions and the CNO cycle, part of stellar nucleosynthesis.

The Sun is a natural nuclear fusion reactor, powered by a proton-proton chain reaction which converts four hydrogen nuclei (protons) into alpha particles, neutrinos, positrons and energy.

Through the 1920s, Arthur Stanley Eddington became a major proponent of the proton-proton chain reaction (PP reaction) as the primary system running the Sun.

In the lower main sequence, energy is primarily generated as the result of the proton-proton chain, which directly fuses hydrogen together in a series of stages to produce helium.

This is believed to be caused by 'thermal pulses', where a shell of helium near the core of the star temporarily becomes hot and dense enough to undergo proton-proton chain.

For a K-type main-sequence star, this fusion is dominated by the proton-proton chain reaction, wherein a series of mergers of four hydrogen nuclei results in a helium nucleus.

FALSE A Helium flash occurs in stars which initiate helium burning by the triple alpha process NOT the proton-proton chain.

The CNO cycle (for carbon-nitrogen-oxygen) is one of the two (known) sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton-proton chain reaction.

For a more-massive protostar, the core temperature will eventually reach 10 million kelvin, initiating the proton-proton chain reaction and allowing hydrogen to fuse, first to deuterium and then to helium.

As seen in figure, Solar neutrinos (proton-proton chain) in the Standard Solar Model, the deuterium will fuse with another proton to create a He nucleus and a gamma ray.

A Helium flash is the rapid burst of energy generation with which a star initiates helium burning by the proton-proton chain process in the degenerate core of a low-mass red giant star.